Method and apparatus for cutting veneer produced by means of turning on a lathe into sheets with uniform fibre configuration

ABSTRACT

A method and apparatus for cutting veneer produced by means of turning on a lathe into sheets by first fitting the surface of the log of the veneer with cut markings that, as viewed from the axis of rotation of the log, lie at least approximately on the same radius or radii and by then cutting the veneer into sheets in accordance with the marks on the veneer surface so that a uniform fibre configuration is achieved. As a cutting mark is used a marking substance that is fed onto the log surface by means of a marking equipment synchronized with the movement of rotation of the log. The cutting mark is indicated by means of an indicator device and the cutter is adjusted to cut off the veneer at any desired phase shift in relation to the marks on the veneer face by using a control unit guided by the indicator equipment.

United States Patent [191 Ervast METHOD AND APPARATUS FOR CUTTING VENEER PRODUCED BY MEANS OF TURNING ON A LATHE INTO SHEETS WITI-I UNIFORM FIBRE CONFIGURATION [75] lnventor: Armas Ervast, Keuruu, Finland [73] Assignee: Messers. Timi 0y, Keuruu, Finland [22] Filed: June 21, 1972 21 App]. No.: 265,019 I [30] Foreign Application Priority Data June 22, 1971 Finland 1772/71 [56] References Cited UNITED STATES PATENTS 2,938,552 5/1960 Rogers.... 3,079,963 3/1963 Jensen 3,244,206 4/1966 Bossen 3,289,581 12/1966 Roozee... 3,521,598 7/1970 Straw 118/9 X May 28, 1974 FOREIGN PATENTS OR APPLICATIONS 590,788 H1934 Germany [44/209 Primary Examiner-Andrew R. Juhusz Assistant Examiner-W D. Bray Attorney, Agent, or Firm-Latins, Parry, Von Gehr, Goldsmith & Deschamps [57] ABSTRACT A method and apparatus for cutting veneer produced by means of turning on a lathe into sheets by first fitting the surface of the log of the veneer with cut markings that, as viewed from the axis of rotation of the log, lie at least approximately on the same radius or radii and by then cutting the veneer into sheets in accordance with the marks on the veneer surface so that a uniform fibre configuration is achieved. As a cutting mark is used a marking substance that is fed onto the log surface by means of a marking equipment synchronized with the movement of rotation of the log. The cutting mark is indicated by means of an indicator device and the cutter is adjusted to cut off the veneer at any desired phase shift in relation to the marks on the veneer face by using a control unit guided by the indicator equipment.

7 Claims, 1 Drawing Figure METHOD AND APPARATUS FOR CUTTING VENEER PRODUCED BY MEANS OF TURNING ON A LATHE INTO SHEETS WITH UNIFORM FIBRE CONFIGURATION The present invention concerns a method for cutting veneer produced by means of turning on a lathe into sheets with uniform fibre configuration by first fitting the surface of the log or of the veneer with cut markings that, as viewed from the axis of rotation of the log, lie at least approximately on the same radius or radii and by then cutting the veneer into sheets in accordance with the marks on the veneer surface.

The invention also concerns an apparatus to be used for carrying out this method and consisting of a marking equipment, indicator equipment, control unit, and cutting device.

So far, a number of methods are known for cutting veneer produced by turning on a lathe into sheets with uniform fibre configuration. The log to be turned may, for example, first be marked so that the veneer being cut by turning is cut off at every rotation of the lathe, or a radial hole may be drilled into the log to be turned and the cutter may be guided by the holes in the veneer mat produced by the hole drilled. The former method is slow, because the lathe must be stopped several times during the turning of each log for marking. When cutting with the guiding or drilled cutting marks, the method has the disadvantage that it is difficult to make the indicator of cutting marks, which controls the cutter, absolutely certainly distinguish the markings made from other holes that may appear in the veneer. Another disadvantage is that unless the mark drilling is made definitely in the most favourable position in the log, which may, moreover, have different positions inside the log and on the outer surface, the drilling causes reduced quantity. and quality of the veneer obtained from the log.

Under these circumstances, there is a need for a cutting method in which the cutting marks used differ sufficiently from the marks appearing in the wood by nature and in which the cutting marks should not damage the veneer.

It has been possible to solve this problem by means of the present invention. The method according to the invention is mainly characterized in that as a cutting mark is used a marking substance that is fed onto the log surface by means of a marking equipment synchronized with the movement of rotation of the log, the cutting mark is indicated by means of an indicator device known per se, and the cutter is adjusted to cut off the veneer at any desired phase shift in relation to the marks on the veneer face by using a control unit guided by the indicator equipment.

The equipment according to the invention is, on the other hand, characterized in that the marking equipment consists of a spraying device that sprays the marking substance as being synchronized with the movement of rotation of the log and that is guided by a spray-control device, and the indicator equipment comprises a lamp transmitting ultra-violet radiation, an ultra-violet filter, and a photo-active unit, and the cutter control unit, which operates on the basis of impulses given by the indicator equipment, is fitted with a phaseshift controller known per so.

By means of the invention an automation of the cutting stage is reached so that, as compared with the methods previously used, a reduction in the number of work operations and savings of raw-material are achieved.

Moreover, the markings are during the turning operation substantially invisible, but they can be detected by means of the indicator.

Further, the cutter can be synchronized by means of these markings, but the cutting does not have to be carried out always exactly at the marking but it may be carried out at any point that is most favourable for the use of raw-material.

Below, the invention will be examined more closely with the aid of the attached drawing, which gives a schematic view of one embodiment of the equipment according to the invention.

The cutting marks are produced during the turning operation by spraying them by means of a spraying device 4 controlled from the lathe shaft 15 onto the veneer 3 being cut by the lathe with a marking substance that is invisible but that can be indicated by means of ultra-violet radiation or of any equivalent means. By means of these marks produced on the veneer 3 the cutter 12 control unit 10 is synchronized, which unit is characterized in a continuous adjustment of phase shift in relation to the marks so that the cutting position can be shifted to any desired point in relation to the marks. Moreover, the control unit 10 is able to operate with the given rhythm even if some cutting marks were left out in between for some reason.

A preferred marking substance is a fluorescent liquid.

Onto the veneer 3 being cut by the blade 2 from the log 1 to be turned, marks are sprayed by means of a fluorescent liquid once per each rotation of the lathe by means of the spraying device 4, which is controlled by means of a spray-control device 5, which senses the control impulses on the lathe shaft 15. The marks, which are invisible in normal light, are indicated at the cutting site by means of an indicator that comprises a lamp 6 giving ultra-violet radiation, an ultra-violet filter 7 that lets through only the part within the range of visible light of the radiation reflected from the cutting mark, and a photo-active unit 8. The entrance of visible light into the inspection point is prevented by means of a protection bulb 9. The photo-active unit 8 controls the cutter control unit 10, which comprises the memory of the cutting rhythm and the adjuster ll of the phase shift.

The synchronization of the marking has been achieved by means of an eccentric section 13 on the lathe shaft 15. As marking substance has been used in the example case an ordinary optical whitewashing substance that is fed through a nozzle 14 onto the surface of the log 1.

The wave length of the radiation transmitted by the ultra-violet lamp 6 is in the example case 365 mm, and the filter 7 is an ordinary yellow filter. The photo-active unit 8 is a photo-resistance, photo-cell or equivalent.

It is evident that in its details the invention may show even considerable variation. Thus, besides a fluorescent substance, it is also possible to use as the marking substance, for example, a phosphorescent, radio-active or magnetic substance. In such cases, of course, an indicator sensitive to each of these particular marking substances has to be used.

What I claim is:

l. A method of cutting a continuous sheet of veneer produced by peeling a log rotating on a lathe into sheet portions, which comprises:

a. applying transverse cutting marks to the continuous sheet being peeled from the log from a source of marking substance actuated intermittently by rotation of the lathe,

b. continuously advancing the marked sheet towards a cutting device,

c. actuating an indicator by passage of a cutting mark past the same, said indicator being located a predetermined distance ahead of the cutting device,

d. operating the cutting device by actuation of the indicator to cut sheet portions having a length determined by the spacing of the markings.

2. A method according to claim 1, characterized in that a fluorescent liquid is used as the marking substance.

3. A method according to claim 1, characterized in that an optical whitewashing substance is used as the marking substance.

4. A method according to claim 1, characterized in that a phosphorescent substance is used as the marking substance.

5. A method according to claim 1, characterized in that a radio-active substance is used as the marking substance.

6. A method according to claim 1, characterized in that a magnetic substance is used as the marking substance.

7. Apparatus for cutting a continuous sheet of veneer produced by peeling a log rotating on a lathe into sheet portions, which comprises:

a. a source of marking substance and means controlled by rotation of the lathe for actuating said source intermittently to apply transverse cutting marks to the continuous sheet being peeled from the log,

b. a cutting device towards which the marked sheet is continuously advanced,

c. an indicator having actuating means responsive to passage of a cutting mark past the same and located a predetermined distance ahead of the cutting device,

d. means for operating the cutting device from said indicator actuating means to cut sheet portions having a length determined by the spacing of the markings. 

1. A method of cutting a continuous sheet of veneer produced by peeling a log rotating on a lathe into sheet portions, which comprises: a. applying transverse cutting marks to the continuous sheet being peeled from the log from a source of marking substance actuated intermittently by rotation of the lathe, b. continuously advancing the marked sheet towards a cutting device, c. actuating an indicator by passage of a cutting mark past the same, said indicator being located a predetermined distance ahead of the cutting device, d. operating the cutting device by actuation of the indicator to cut sheet portions having a length determined by the spacing of the markings.
 2. A method according to claim 1, characterized in that a fluorescent liquid is used as the marking substance.
 3. A method according to claim 1, characterized in that an optical whitewashing substance is used as the marking substance.
 4. A method according to claim 1, characterized in that a phosphorescent substance is used as the marking substance.
 5. A method according to claim 1, characterized in that a radio-active substance is used as the marking substance.
 6. A method according to claim 1, characterized in that a magnetic substance is used as the marking substance.
 7. Apparatus for cutting a continuous sheet of veneer produced by peeling a log rotating on a lathe into sheet portions, which comprises: a. a source of marking substance and means controlled by rotation of the lathe for actuating said source intermittently to apply transverse cutting marks to the continuous sheet being peeled from the log, b. a cutting device towards which the marked sheet is continuously advanced, c. an indicator having actuating means responsive to passage of a cutting mark past the same and located a predetermined distance ahead of the cutting device, d. means for operating the cutting device from said indicator actuating means to cut sheet portions having a length determined by the spacing of the markings. 